Minor optimization (replace data_part_ascii_no_checksum)

Author: optout21

lightning-invoice/src/de.rs

@@ -364,10 +364,8 @@ impl FromStr for SignedRawBolt11Invoice {
 	fn from_str(s: &str) -> Result<Self, Self::Err> {
 		let parsed = CheckedHrpstring::new::<Bech32>(s)?;
 		let hrp = parsed.hrp();
-		// Access original non-packed 32 byte values (as ascii + conversion)
-		let data: Vec<_> = parsed.data_part_ascii_no_checksum().iter()
-			.map(|ch| Fe32::from_char(char::from(*ch)).expect("value should be < 32"))
-			.collect();
+		// Access original non-packed 32 byte values (as Fe32s)
+		let data: Vec<_> = parsed.fe32_iter::<alloc::boxed::Box<dyn Iterator<Item = u8>>>().collect();
 
 		const SIGNATURE_LEN5: usize = 104; // 32-bit values, 65 bytes
 		if data.len() < SIGNATURE_LEN5 {